Abstract: The effect of Ti added in Zn bath on HDG (Hot Dip Galvanizing) process of steel plate was studied using SEM.The results show that, when the titanium content in the zinc bath increased, the growth of ζ phase in coating was restrained distinctly, the thickness of coating decreased.Titanium can effectively restrain the excess growth of coating for reactive steel containing silicon during the hot dip galvanizing process.When the titanium content in the zinc bath was over 0.05%, the Γ₂ phase particles were formed in the coating.Adding 0.03%~0.05%Ti to Zn bath for 0.09% Si steel could completely restrain the Sandelin effect.But adding titanium to the zinc bath had no effect on the 0.36% Si steel.